package com.aisino.interceptor;

import com.aisino.annotation.UserLoginToken;
import com.aisino.entity.User;
import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.exceptions.JWTVerificationException;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.lang.reflect.Method;

/**
 * @author guochuantao
 * @version 1.0
 * @description JWT拦截器
 * @since 2024/7/22 下午1:48
 */
@Configuration
public class RequireJwtInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        // String token = request.getHeader("token");// 从 http 请求头中取出 token
        String token = request.getHeader("authorization");// 从 http 请求头中取出 token   授权
        // 如果不是映射到方法直接通过
        if(!(handler instanceof HandlerMethod)){
            return true;
        }
        HandlerMethod handlerMethod=(HandlerMethod)handler;
        Method method=handlerMethod.getMethod();
        //检查是否有passtoken注释，有则跳过认证
/*        if (method.isAnnotationPresent(PassToken.class)) {
            PassToken passToken = method.getAnnotation(PassToken.class);
            if (passToken.required()) {
                return true;
            }
        }*/
        //检查有没有需要用户权限的注解
        if (method.isAnnotationPresent(UserLoginToken.class)) {
            UserLoginToken userLoginToken = method.getAnnotation(UserLoginToken.class);
            if (userLoginToken.required()) {
                // 执行认证
                if (token == null) {
                    throw new RuntimeException("无token，请重新登录");
                }
                // 获取 token 中的 user id
                String userId;
                try {
                    token = token.replace("Bearer ", "");
                    userId = JWT.decode(token).getAudience().get(0);
                } catch (JWTDecodeException j) {
                    throw new RuntimeException("401");
                }

                //demo写死了用户id
                System.out.println("userId = " + userId);
                User user = null;
                if ("1314520".equals(userId)) {
                    user = new User();
                    user.setUsername("admin");
                    user.setPassword("123456");
                }

                //真实场景需要从库里查询
                // User user = userService.findUserById(userId);
                if (user == null) {
                    throw new RuntimeException("用户不存在，请重新登录");
                }
                // 验证 token
                JWTVerifier jwtVerifier = JWT.require(Algorithm.HMAC256(user.getPassword())).build();
                try {
                    jwtVerifier.verify(token);
                } catch (JWTVerificationException e) {
                    throw new RuntimeException("授权信息token已过期");
                }
                return true;
            }
        }
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        HandlerInterceptor.super.postHandle(request, response, handler, modelAndView);
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        HandlerInterceptor.super.afterCompletion(request, response, handler, ex);
    }
}
